A refrigerant evaporator functions as a cooling heat exchanger configured to cool a subject-to-cooling fluid (for example, air) by absorbing heat from the subject-to-cooling fluid flowing outside to evaporate the refrigerant (liquid-phase refrigerant) flowing inside.
Examples of the known refrigerant evaporator of this type include a configuration in which first and second evaporators each provided with a heat exchanging core unit having multiple stacked tubes and a pair of tank units connected to both end portions of the multiple tubes are arranged in series in a flowing direction of the subject-to-cooling fluid, and one of the tank units of the respective evaporators are coupled via a pair of communicating portions (For example, see Patent Document 1).
In the refrigerant evaporator disclosed in Patent Document 1, when refrigerant flowing in a heat exchanging core unit of the first evaporator is flowed to a heat exchanging core unit of the second evaporator via one of the tank units of the respective evaporators and the pair of communicating portions that couples the tank units, the flow of the refrigerant is switched in the width direction (lateral direction) of the heat exchanging core units. In other words, in the refrigerant evaporator, refrigerant flowing on one side in the width direction of the heat exchanging core unit of the first evaporator via one of the pair of communicating portions flows to the other side in the width direction of the heat exchanging core unit of the second evaporator, and refrigerant flowing on the other side in the width direction of the heat exchanging core unit of the first evaporator by the other communicating portion flow to one side in the width direction of the heat exchanging core unit of the second evaporator.
Patent Documents 1 to 3 disclose refrigerant evaporators. The disclosed refrigerant evaporators each absorb heat from a subject-to-cooling fluid flowing outside, for example, air, and evaporate the refrigerant flowing inside. As a result, the refrigerant evaporator functions as a cooling heat exchanger configured to cool the subject-to-cooling fluid. The disclosed refrigerant evaporator further includes a first evaporator and a second evaporator arranged in series on an upstream side and a downstream side in a flowing direction of the subject-to-cooling fluid. Each evaporator includes a core portion having multiple stacked tubes and a pair of the tank units connected to both end portions of the multiple tubes. The core portion of the first evaporator is zoned in the width direction, that is, the lateral direction. The core portion of the second evaporator is also zoned in the width direction, that is, the lateral direction.
The refrigerant evaporators disclosed in Patent Documents 1 to 3 are each provided with an exchanging unit configured to exchange the refrigerant in the lateral direction at a communicating portion in which the refrigerant flows from the first evaporator on the downstream side to the second evaporator on the upstream. The exchanging unit is provided by the two communicating portions. One of the communicating portions is configured to lead refrigerant flowing out from one portion of the first evaporator, for example, from the right side portion to the other portion of the second evaporator, for example, to the left side portion. The other communicating portion is configured to lead the refrigerant flowing out, for example, from the other portion, that is, the left side portion of the first evaporator to one portion of the second evaporator, for example, to the right side portion. The exchanging unit may also be referred to as an intersecting flow channel.
Patent Document 4 discloses a refrigerant evaporator. The disclosed refrigerant evaporator is provided with a throttle member in the tank in order to adjust distributing properties of the refrigerant to multiple heat exchanging tubes.